Art of converting hydrocarbon oils into lower boiling products



' June 1,1926; 1,586,994

r F. A. HOWARD ART OF CONVERTING HYDROCARBON OILS INTO LOWER BOILING PRODUCTS Filed August 16. 1922 TANK RECEIVING.

CONDENSER BOILER CONDENSER which forms ajacket for Patented 'June 1 1926 UNITED STATE-S PATENT OFFICE;

FRANK A. nowam), or ELIZABETH, NEW JERSEY, Assrenon T0 STANDARD DEvEL- ornrnlv'r' co'mrnnv, A CORPORATION or n'nnnwnnns. 4

ART or ooivvnnrme HYDROCARBON OILS rnro LOW R nornine rnonucr's.

Application filed August 16, 1922. seen No. 582,113.

invention relates to the art of cracking or obtaining lighter products from .drocarbons by aid of heat, and will lac-fully,

understood from the following description taken in connection with the accompanying drawing which represents. semi-diagram-' matically one form of embodiment of the invention. In subjecting hydrocarbons to heat In the present types of apparatus a general difiiculty encountered is the occurrence of localized overheating. lVher'e Working at the relatively high temperatures of pressure distillation or cracking, coke patches and hot spots develop on the still or tube walls, occasioning not. only a rapid deterioration of the apparatus, but necessitating not infre-- .quently ajpremature discontinuance of the run.

By the present invention I avoid such undue and irregular concentration of heat upon areas of thestill, or tubes, or other heating surface, as would'be primarily favorable to the starting of .spot.cok1ng, and I am moreover enabledto transmit heat into the oil inthe still by a much lower temperature gradient from the heating side.

' Referring more particularly to the drawing, reference character -1 designates a suit .able means for holding oil heated, and which'may be, for example,- a shell still or acracking drum or tube or as sembly of tubes. Leading from the oil heater is an outlet pipe. In the'case of a still this will more particularly be a vapor pipe 3 connecting w1th a reflux condenser 1, and proceeding therefrom is a 'plpe 5 leading to a suitable water cooled condenser 6 and receiving tank 7 A run-back pipe 16 is provided for returning reflux from condenser 4 to thestill, and a pipe 17 may be used to by-pass the reflux condenser'when desired, j the valves 18 and 19 being closed on' such occasions and valve 20 being opened. Spaced about the wall of the oil heater is agcasing 8 a heating fluid delivered at an advantageous distributing point bya pipe 11 from a suitable boiler 12 mounted in a 'furnace chamber 10; 'The detailed construction of the boiler may advantageously be, for instance, that set forth inthe application of F.'A. Howard,W. K. Lewis B and H.- M. Noel, Serial No. 551,300, filed b April 10, 1922; and I em loy. as heating medium mercury or a suitab e vaporizable non;

while beingtween 700 and 1000 .what' upon the corrosive ino-rganicsalt or organic -com pound. Mercury is advantageous in -that'its I vapors are available ata range of temperain verymoderate limits, for instance at a gauge pressure of 40 pounds the saturated mercuryvapors have a temperature of about he vapors may also besuperheated if desired. '7

.And with any of the materials contemplated, temperatures up to 1000? F. may be attained Without the pressure of exceeding. 200' pounds.

A return pipe 14' com'pletesthe circuit for the'used heating medium back to the boiler, and it will be tu'res-suitable and the pressures'remainwith-1' the medium understood that the jacket;

and boiler circuit is-a closedsystem which is exhausted of air. of heat-transmitting medium has been originally placed in'the boiler. I Suitable thermometers and pressure gauges (not-shown) are provided on the boiler and still, lines 11 and 14.- 4

A covering of insulation 9. is provided and sealed after the charge also control-valves on the about'the oil heater to cut down unnecessary heat losses.

In operation, hydrocarbon oil of desired character is charged into the oil heater 1 or '7 1s fed. continuously therethrough and the' heating fluid is supplied from the boilerat the desired temperature, for instance be F, depending somepartlcularoil employed,"precise regulation the pressure in the heatingjacket. The .dis-

tillation vapor passes over through the vaporline 3 is freed of undesirable heavy constituents lay the reflux condenser 4 and is finally condensed in the water-cooled'condenser 6. reflux condenser, however,"may be by passed, if desired, by openin closing the valves 18 and 19. l. at-ever pressure is desired in the oil; heater 1 is maintained by adequate closure or'regulation of the valve 15 on the gas-line from the receiving tank or by a'valve 21- in front. ofthe eing secured by controlling.

valve 20 and condenser 6 if it is preferred not to Hold the I condenser under the same,,,pre'ssure as the still. In some cases temperature regulation may be secured by controlling the. pressure. y leaving all valves open, the pressure can e maintained substantially atmospheric, but generally. Irprefer higher pressures, for instance lbs, 350 lbs, etc. While, as artswhich a gang of tubes is employed, the entire gang may be enveloped 3acket or the tubes may position at such temperatures, subjecting the hydrocarbon to indirect heat of the vapors of suchsubstance range specified, whereby the hydrocarbons are cracked by uniformly applied heat, taking ofi' vaporous cracked products, and condensing the same.

tomary, the run may continue down to tar bottoms, I also contemplate, Where using a shell still, running the oil down to complete dry11ess,'obtaining in this manner a materially increased yield. Where applying my invention to tube stills or' cracking coils in l in the heating be individually jacketed as may be preferred.

The advantages of my invention While in practice mostly desiredwith liquid oils, extend also to solid materials from which light hydrocarbons may be distilled off.

While in describing my invention I have referred to certain specific details, it will be understood that thisis with the intent of explanatory illustration rather than limitation. Nor is the invention to be considered as'in any Way'dependent upon the accuracy of any theories or reasons advanced to explain the advantageous results attained. On the contrary, it is limited only as defined in the following claims, in which it is my intention to claim all inherent novelty as broadly as the prior art-permits.

What I claim is 1. Process of cracking hydrocarbons, con prisingheating in a closed system a substance which at a temperature of -700 to 1000 F. exerts a pressure of less than 200 lbs. per sq. in. and is stable against decome the hydrocarbons are distilled substantially to dryness.

prising heating mercury in a closed system to a temperature above 700 F., subjecting the hydrocarbons to indirect heat of the mercury vapor at such temperature, whereby the hydrocarbons are cracked by uniformly applied heat, taking off vaporous cracked products, and condensing the same.

4. Apparatus. for cracking hydrocarbons, comprising a still, a vapor pipe leading from said still,\a condenser'for vapors from the still, a casing about the still, and a heating system for the still and including'means for supplying to the casing at a temperature above 700 F., a vaporized material which at'temperatures of 700 to 1000 F. exerts a pressure less than 200 lbs. per sq. in. and

FRANK A. HOWARD.

within the temperature 2. 'Process according to claim 1 in which '3. Process of cracking hydrocarbons, comis stable against decomposition at such tem-. 

